Richard Handl said he had the radioactive elements radium, americium and uranium in his flat in southern Sweden when the police showed up.

He said on Wednesday he had always been interested in physics and chemistry and "just wanted to see if it was possible to split atoms at home".

Handl never tried to hide what he was doing. In fact, according to The Local, an English-language news site from Sweden, police went to his apartment after he contacted the Swedish Radiation Authority to ask if it was legal to build a nuclear reactor.

Handl even kept a blog about his adventures. He wrote about how he got radioactive Americium from a smoke detector and he posted a picture of a vial filled with glowing tritium.

"I had just bought what was needed, so I do not know if it had worked," he told HD, according to a Google translation of the piece. "It's probably pretty hard to get it to work. But they took all my stuff, so now I'm done. Now I'll keep it at the theoretical level," he said.